Generally a heart potential diagram is taken in a clinical diagnosis of a heart disease. Not only in the clinical diagnosis and prevention of a heart disease but also on the health control in the daily life, if a heat potential diagram can be taken promptly as required and waveforms catching abnormal heart muscles or irregular pulses are obtained, if will be very convenient.
There is already such portable heat potentiometer as a folder heat potentiometer wherein heart potential waveforms are recroded in a cassete tape. However, there have been defects that this folder heart potentiometer is so complicated to fit and so comparatively large in form and weight as to be a considerable burden to be carried by a patient and that, as the time when the fit of a heart occurs is not known and the fit is temporary, even if the folder heart potentiometer is fitted, there will be often nothing abnormal and no sufficient effect will be able to be obtained with the required toil.
Therefore, there is recently provided a small light heart potentiometer in which a semiconductor memory is contained and the above mentioned defects are improved. That is to say, this heart potentiometer is generally in the form of a disk having a proper thickness and provided with electrodes respectively on the upper and lower surfaces. In the use, as shown in FIG. 8, a heart potentiometer 31 is held with a right hand 19 and is pressed against such part to be measured as a breast. In this case, one electrode is contacted with the breast or the like and the other electrode is contacted with the palm of a hand to induce a heart potential. However, the form will be thin disk-like, an excess force may be applied to use it and a finger tip 19a will contact the breast. Therefore, there have been defects that the potential difference will reduce or vanish and a noise will mix in to make it difficult to measure accurate heart potential waveforms.